Related papers: Proton Spin in Chiral Quark Models
A direct connection can be made between mixing angles in negative parity baryons and the spin coupling of constituent quarks. The mixing angles do not depend on spectral data. These angles are recalculated for gluon exchange and pion…
Using an SU(3) flavour symmetry breaking expansion in the quark mass, we determine the QCD component of the nucleon, Sigma and Xi mass splittings of the baryon octet due to up-down (and strange) quark mass differences in terms of the kaon…
We calculate the leading-twist helicity-dependent generalized parton distributions (GPDs) of the proton at finite skewness in the Nambu--Jona-Lasinio (NJL) model of quantum chromodynamics (QCD). From these (and previously calculated…
We discuss the SU(3) and heavy quark spin-symmetry breaking mixing between the Xi_c and Xi'_c charmed baryons. Chromomagnetic hyperfine interactions are the leading source of spin-symmetry breaking and together with the SU(3) breaking mass…
In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be…
We calculate the quark spin contribution to the total angular momentum of flavor octet and flavor decuplet ground state baryons using a spin-flavor symmetry based parametrization method of quantum chromodynamics. We find that third order…
The SU(3) breaking effects due to light quark masses on heavy meson masses, decay constants ($F_{D}, F_{D_{s}}$) and the form factor for semileptonic $\overline{B}\rightarrow D^{(\ast)} l\bar{\nu}_{l}$ transitions are formulated in chiral…
We investigate the electromagnetic transitions of the singly charmed baryons with spin 3/2, based on a pion mean-field approach, also known as the chiral quark-soliton model, taking into account the rotational $1/N_c$ corrections and the…
We investigate the mechanics of the proton by examining the flavor-decomposed proton cosmological constants and generalized vector form factors. The interplay of up, down, and strange quarks within the proton is explored, shedding light on…
We examine the effects of SU(3) breaking in the matrix elements of the flavour-diagonal axial currents between octet baryon states and find that SU(3) breaking may be substantial for some matrix elements. We estimate the strange axial…
The two-pion exchange interaction between constituent quarks is shown to enhance the effect of the the isospin dependent spin-spin component of the one-pion exchange interaction, and to cancel out its tensor component. It therefore provides…
We study $pp$ scattering at high energies and moderately large momentum transfer using a QCD--based model in which the proton is viewed as being composed of a quark and a diquark. This model leads to spin asymmetries which are neither small…
The proton is one of the main building blocks of all visible matter in the universe. Among its intrinsic properties are its electric charge, mass, and spin. These emerge from the complex dynamics of its fundamental constituents, quarks and…
A classification scheme of hadrons is proposed on the basis of the division algebra H of quaternions and an appropriate geometry. This scheme suggests strongly to understand flavour symmetry in another manner than from standard symmetry…
It is shown that the observed small value of the integrated spin structure function for protons could be naturally understood within the naive quark model by considering the effect from Melosh rotation. The key to this problem lies in the…
Nucleon, pion and quark form factors are studied within the relativistic harmonic oscillator model including the quark spin. It is shown that the nucleon charge, magnetic and axial form factors and the pion charge form factor can be…
Infra-red properties of the triangle anomaly and the ``anomaly pole'' are elaborated and applied to the study of high-energy scattering in QCD, when the gauge symmetry is partially broken to SU(2). It is shown that the chiral flavor anomaly…
The interaction mediated by irreducible pion and gluon exchange between constituent quarks is calculated and shown to have a strong tensor component, which tends to cancel the pion exchange tensor interaction between quarks. Its spin-spin…
Using an SU(3)-flavour symmetry breaking expansion between the strange and light quark masses, we determine how this constrains the extrapolation of baryon octet matrix elements and form factors. In particular we can construct certain…
In this study, the proton is taken as an ensemble of quark-gluon Fock states. Using the principle of detailed balance, the probabilities of finding every Fock states of the proton are obtained without any parameter. A new origin of the…